Tokyo Electric Power’s move to pull the plug on an agreement with Canadian uranium miner Cameco Corp. is the latest example of a company arguably stretching the traditional use of a force majeure or “Act of God” clause to suspend a contract.

Tokyo Electric Power Co. Holdings Inc. argues that it has been unable to operate its nuclear power plants in Japan because of government regulations enacted after the 2011 Fukushima nuclear disaster. The accident was caused by an earthquake and resulting tsunami. Centuries of legal tradition should easily place those natural disasters within anyone’s definition of Acts of God.

You probably can’t say that for government-made regulation, though Tepco’s obvious point is there wouldn’t be regulation but for those preceding Acts of God. Maybe it is legally possible to say those natural disasters started a chain reaction of unforeseeable events, including more government regulation. It depends on the wording of the force majeure clause in the contract between Tepco and Cameco.

For now at least, Cameco won’t disclose the wording used in the clause. “It does contain provisions when force majeure and other defences can be taken advantage of, but I don’t think we’ll get into any more detail right now,” said Sean Quinn, senior vice-president and chief legal officer of Cameco, during a conference call earlier this month. “We don’t think this is a situation that falls into any of the categories that would excuse Tepco.”

A force majeure clause is supposed to absolve a party from executing on an agreement due to circumstances beyond the control of the parties.

A typical clause covers Acts of God. I am a proud alumni of the Sunday School at Zion Lutheran Church in Dashwood, Ont. Pastor Mellecke took us through quite a catalog of God’s wrath – things like floods, pestilence, storms, famines, and earthquakes. But you probably don’t need bible school training to know an Act of God when you see it. For a quick primer, watch Charlton Heston’s Moses open a few cans of biblical whoop-ass in Cecil B. DeMille’s 1956 classic, The Ten Commandments.

Over the years, lawyers have decided the Old Testament alone doesn’t cover enough contract risk. They’ve added several man-made events to force majeure clauses, such as labour disputes, wars, and blackouts.

Here’s the legal problem. If an event isn’t already built into a force majeur list, it can be very difficult to argue that a court or arbitrator should read it in. Commodity prices, market conditions and changes to government policy are examples of risks that can be reasonably foreseen by business people. If those risks should allow a party to cease or suspend execution of the agreement, the parties need to include them in the deal, either as part of the force majeure clause or in some other termination provision.

This doesn’t always happen.

Koji Sasahara/Pool via Bloomberg

Donald Trump, whom you might have heard of, once argued in court that he should be able to delay monthly payments on a real estate loan because the financial crisis of 2008-2009 was an “Act of God.” The case was settled out of court in 2010.

In a Canadian example, a company called Univar Canada Ltd. tried to invoke force majeure to get out of an agreement to supply Domtar Inc. with caustic soda at a fixed price. Market conditions changed and the price shot above the contract price. Univar claimed force majeure, but a B.C. judge disagreed in 2011.

For its part, Cameco has publicly said the Tepco dispute is likely more about the prices written into the contract than Acts of God or government regulation. We likely won’t know until the dispute is resolved.

The contract first requires Cameco and Tepco to engage in a 90-day “good faith” negotiation period.

According to a 2014 Supreme Court of Canada case called Bhasin v. Hrynew, “good faith” requires parties to perform their contractual obligations honestly. In other words, Cameco and Tepco can’t cross their fingers and fake their way through negotiations. And there’s little reason to expect anything less. Tepco holds a five per cent stake in Cameco’s Cigar Lake mine in Saskatchewan and has continued to contribute its share to capital costs.

If good faith talks can’t resolve the dispute, the contract calls for binding arbitration. The parties would take the dispute to a private court, where an arbitrator would interpret the contract behind closed doors. Cameco says it won a force majeure contract dispute in 2014, though confidentiality terms prevent it from providing further details.

Things do happen that make it impossible to execute on deals, but not every one of those things is an Act of God.